For an attic measuring 40' x 32', how many square inches of venting should be provided?

To determine the amount of venting needed for an attic, a common guideline is to allocate 1 square foot of venting for every 300 square feet of attic space.

First, calculate the total area of the attic. Multiplying the length by the width gives:

40 feet x 32 feet = 1280 square feet.

Next, divide the total attic area by 300 to find the required square footage of venting:

1280 square feet ÷ 300 = 4.27 square feet.

Since venting is typically measured in square inches, convert square feet to square inches. There are 144 square inches in a square foot (12 inches x 12 inches), so:

4.27 square feet x 144 square inches/square foot = 614.88 square inches.

To apply the rule more accurately and understand better, it is common to round up as necessary when providing venting, so the nearest practical number would be 640 square inches. This matches the provided answer, indicating it is essential to follow standard guidelines for ventilation to ensure proper air circulation in the attic space and prevent moisture buildup, which can lead to roofing and structural issues over time.

Thus, the total venting requirement for the attic should